Commit message: Disallow division by zero FPE in `tf.raw_ops.ResourceScatterDiv`

Had to update a test that was broken.

PiperOrigin-RevId: 388516976
Change-Id: Ic358e6bf0559e011539974d453fc7aa18b427e9c
CVE: CVE-2021-37642
CWE: CWE-369
Vulnerability description: TensorFlow is an end-to-end open source platform for machine learning. In affected versions the implementation of `tf.raw_ops.ResourceScatterDiv` is vulnerable to a division by 0 error. The [implementation](https://github.com/tensorflow/tensorflow/blob/8d72537c6abf5a44103b57b9c2e22c14f5f49698/tensorflow/core/kernels/resource_variable_ops.cc#L865) uses a common class for all binary operations but fails to treat the division by 0 case separately. We have patched the issue in GitHub commit 4aacb30888638da75023e6601149415b39763d76. The fix will be included in TensorFlow 2.6.0. We will also cherrypick this commit on TensorFlow 2.5.1, TensorFlow 2.4.3, and TensorFlow 2.3.4, as these are also affected and still in supported range.

Project: tensorflow
File: resource_variable_ops.cc

  void DoCompute(OpKernelContext* c) {
    core::RefCountPtr<Var> v;
    OP_REQUIRES_OK(c, LookupResource(c, HandleFromInput(c, 0), &v));
    Tensor* params = v->tensor();
    const Tensor& indices = c->input(1);
    const Tensor& updates = c->input(2);

    // Check that rank(updates.shape) = rank(indices.shape + params.shape[1:])
    OP_REQUIRES(c,
                updates.dims() == 0 ||
                    updates.dims() == indices.dims() + params->dims() - 1,
                errors::InvalidArgument(
                    "Must have updates.shape = indices.shape + "
                    "params.shape[1:] or updates.shape = [], got ",
                    "updates.shape ", updates.shape().DebugString(),
                    ", indices.shape ", indices.shape().DebugString(),
                    ", params.shape ", params->shape().DebugString()));

    // Check that we have enough index space
    const int64_t N_big = indices.NumElements();
    OP_REQUIRES(
        c, N_big <= std::numeric_limits<Index>::max(),
        errors::InvalidArgument("indices has too many elements for ",
                                DataTypeString(DataTypeToEnum<Index>::v()),
                                " indexing: ", N_big, " > ",
                                std::numeric_limits<Index>::max()));
    const Index N = static_cast<Index>(N_big);
    OP_REQUIRES(
        c, params->dim_size(0) <= std::numeric_limits<Index>::max(),
        errors::InvalidArgument("params.shape[0] too large for ",
                                DataTypeString(DataTypeToEnum<Index>::v()),
                                " indexing: ", params->dim_size(0), " > ",
                                std::numeric_limits<Index>::max()));

    if (N > 0) {
      auto indices_flat = indices.flat<Index>();
      auto params_flat = params->flat_outer_dims<T>();
      if (TensorShapeUtils::IsScalar(updates.shape())) {
        const auto update = updates.scalar<T>();

        functor::ScatterScalarFunctor<Device, T, Index, op> functor;
        const Index bad_i = functor(c, c->template eigen_device<Device>(),
                                    params_flat, update, indices_flat);
        OP_REQUIRES(c, bad_i < 0,
                    errors::InvalidArgument(
                        "indices", SliceDebugString(indices.shape(), bad_i),
                        " = ", indices_flat(bad_i), " is not in [0, ",
                        params->dim_size(0), ")"));
      } else {
        int64_t num_updates = updates.NumElements();
        OP_REQUIRES(
            c, TensorShapeUtils::StartsWith(updates.shape(), indices.shape()),
            errors::InvalidArgument(
                "The shape of indices (", indices.shape().DebugString(),
                ") must be a prefix of the shape of updates (",
                updates.shape().DebugString(), ")"));
        auto updates_flat = updates.shaped<T, 2>({N, num_updates / N});

        functor::ScatterFunctor<Device, T, Index, op> functor;
        const Index bad_i = functor(c, c->template eigen_device<Device>(),
                                    params_flat, updates_flat, indices_flat);
        OP_REQUIRES(c, bad_i < 0,
                    errors::InvalidArgument(
                        "indices", SliceDebugString(indices.shape(), bad_i),
                        " = ", indices_flat(bad_i), " is not in [0, ",
                        params->dim_size(0), ")"));
      }
    }
  }